severe or life-threatening allergic reaction in which the blood vessels dilate, causing a drop in blood pressure/ hypotension, and the tissues lining the respiratory system swell, interfering with the airway.

Possible causes of allergic reactions

-Insects, stings (bees, wasps, hornets, yellow jackets)

-Foods (nuts, eggs, milk, shellfish)

-Plants (poison ivy, sumac, oak)

-Medications (penicillin)

-Dust, chemicals, soaps, makeup, latex

Hives

Red, itchy, possibly raised blotches on the skin often result from allergic reactions.